Cambridge Past Paper Questions
Browse 23,045questions from 25 years of O-Level & A-Level exams. Click any question to practice.
Sulfur dioxide can be catalytically oxidised by an oxide of nitrogen in the atmosphere. Which reaction shows the regeneration of the catalyst?
Compound Y is treated with an excess of hydrogen gas in the presence of a nickel catalyst. The product is fully saturated. [Diagram of compound Y] ...
Which equation represents a valid propagation step in the chlorination of ethane?
Maleic acid is used in the food industry and for stabilising drugs. It is the cis-isomer of butenedioic acid and has the structural formula HO2CCH=...
Primary halogenoalkanes undergo hydrolysis reactions. Which reaction would occur most rapidly if they are all warmed to the same temperature?
Structural isomerism and stereoisomerism should be considered when answering this question. A colourless liquid, C5H11Cl, exists as a mixture of tw...
When warm water is added to halogenoalkane X, an SN1 reaction occurs. AgNO3(aq) is then added; a yellow precipitate is formed. What could be X?
Which statement about butanone is correct?
Ethanal, CH3CHO, is used to make product R in a three-stage synthesis. CH3CHO →product P (HCN/NaCN) →product Q (H2SO4(aq), reflux) →product R (conc...
The infra-red spectrum of an organic compound is shown. [Infra-red spectrum graph] Which compound could give this spectrum?
For complete combustion, 1 mol of an organic compound X requires 2.5 mol of O2. Which compounds could be X? 1 C2H5OH 2 C2H2 3 CH3CHO
In which pairs do both species have the same number of electrons? 1 ³⁵Cl and ³⁷Cl 2 ³⁵Cl⁻ and ⁴⁰Ar 3 ⁴⁰Ar and ⁴⁰K⁺
For which reactions does the value of ∆H represent both a standard enthalpy change of combustion and a standard enthalpy change of formation? 1 C(s...
The temperature of a reversible gas phase reaction is increased. Which statements are always correct? 1 More product is present at equilibrium. 2 T...
Three samples of chlorine gas each contain 0.710g of chlorine. Each sample is reacted with a reagent. • In the first reaction a sample is reacted c...
Solid barium oxide is added to some ammonium sulfate solution in a test-tube and the mixture is warmed. A piece of damp red litmus paper is held ov...
Which compounds show geometrical (cis-trans) isomerism? 1 CH3CH=C(CH3)C2H5 2 CH3CH=CHCH2CH2CH3 3 C2H5CH=CHC2H5
Which pairs of compounds may be distinguished from each other by testing with alkaline aqueous iodine? 1 ethane-1,2-diol and ethanol 2 propan-2-ol ...
The diagram shows an experimental set-up which can be used in several different experiments. [Diagram of experimental set-up] Which processes could...
The ester C2H5CO2CH2CH2CH3 can be made in a school or college laboratory by a sequence of four reactions or fewer using compound Z as the only orga...
Sulfuric acid is manufactured by the Contact process. One stage in this process is the conversion of sulfur dioxide into sulfur trioxide in the pre...
Crude oil is a complex mixture of hydrocarbon molecules. The hydrocarbon molecules in crude oil are separated by fractional distillation. Fractiona...
The elements in the third period exhibit periodicity in both their chemical and physical properties.
X is CH3CH(OH)CH2CH3.
Sodium and magnesium are the first two elements in the third period.
Ammonium iron(II) sulfate, (NH4)2Fe(SO4)2, has a relative formula mass, M₁, of 284.
Most vehicle fuels contain hydrocarbons obtained from crude oil.
W is CH3COCH2CH3.
The elements sodium to chlorine, in the third period, all form oxides.
One reason for the wide variety of organic compounds is isomerism, either structural isomerism or stereoisomerism.
The elements in Group 17, the halogens, show trends in both their chemical and physical properties. The elements and their compounds have a wide va...
A is CH3CHBrCH2CH3.
In this question you will determine the identity of the halogen in compound W. Compound W is the halogenoethanoic acid CH2XCO₂H, where X is a halog...
2 In this experiment you will determine the enthalpy change, ∆H, for the decomposition of calcium hydroxide to calcium oxide. Ca(OH)2(s) → CaO(s) +...
2 When an acid reacts with an alkali the neutralisation reaction is always exothermic. H⁺(aq) + OH⁻(aq) → H₂O(l) You will determine the enthalpy ch...
Sodium oxide, Na2O, is a white crystalline solid with a high melting point.
Nitrogen monoxide, NO(g), reacts with hydrogen, H2(g), under certain conditions. 2NO(g) + 2H2(g) → N2(g) + 2H2O(g)
Complete the table, identifying the substance liberated at each electrode during electrolysis with inert electrodes.
Copper is a transition element with atomic number 29.
(a) Benzene reacts with D in the presence of a suitable catalyst to give cumene and non-organic product E. This is an electrophilic substitution re...
The three substances shown all have some acidic properties. [Figures of propanoic acid, propan-1-ol, phenol]
Abscisic acid, C15H20O4, is a plant hormone. [Figure of abscisic acid structure]
Noradrenaline is a hormone found in humans. [Figure of noradrenaline structure]
Silicon tetrachloride, SiCl4, is formed when silicon reacts with chlorine under suitable conditions. It is a colourless liquid with a low boiling p...
Iodine monochloride, ICl, is a yellow-brown gas. It reacts with hydrogen gas under certain conditions as shown. 2ICl(g) + H2(g) → 2HCl(g) + I2(g) E...
Complete the table by predicting the identity of the substance liberated at each electrode during electrolysis with inert electrodes. electrolyte |...
Cobalt is a transition element with atomic number 27. Cobalt forms ions with charges of +2 and +3. Both these ions form complexes.
Phenol is an important industrial chemical used in the manufacture of dyestuff and other substances.